TechSoup.org The place for nonprofits, charities, and libraries

Guide to Microsoft Server Licensing

The basics of Microsoft server licensing, models, and operating system environments

Microsoft logo 
TechSoup - November 11, 2012
Learn the basics of Microsoft server licensing, including licensing models and licensing operating system environments.

This page provides an overview of Microsoft server licensing. You can also visit Microsoft's Product Licensing Search page for detailed licensing information on individual products and product families, including current Product Use Rights (PUR) documents.

Licensing Models

Understanding licensing requirements will help you plan your server implementation. This section provides a brief overview of the three basic licensing models. You can also see the Licensing Model Categories section on Microsoft's About Licensing page.

Server Operating Systems and Server/CAL

The Server Operating Systems and Server/CAL models include server licenses, client access licenses (CALs) for users or devices with connections to the servers, and optional external connector licenses for connecting people who are not employees or onsite contractors (usually through the Internet).

Per Processor or Per Core

The Per Processor or Per Core model includes only server licenses. Each license is valid for a certain number of processors or processor cores, so server applications that run on multiple processors or cores on a single server computer might require multiple licenses. In some cases, only physical processors or cores need to be licensed, while virtual processors or cores (processors or cores recognized in a virtual environment) must be licensed for certain products.

Some server products can be licensed in either the Server/CAL or Per Processor/Per Core models. You can determine which licensing model TechSoup products use by examining the server product name and by checking whether TechSoup offers CALs for that server.

Management Servers

The Management Servers model includes server licenses, server management licenses (MLs) for the servers that are being managed, and client MLs for the nonserver operating system environments that are being managed.

Licensing Operating System Environments

Server operating systems and server applications can run in either physical or virtual operating system environments (OSEs). When your servers or other devices have multiple OSEs, you should check the OSE licensing requirements carefully.

For example, many Microsoft server licenses can be used for only a single operating system environment. When this is the case, if the server operating system or application is installed in more than one environment on a single server computer, a separate license is required for each environment. However, other Microsoft server licenses can be used in both the physical operating system environment and in one or more virtual environments.